August 6, 2015

expert reaction to two papers reporting having converted skin cells into neurons using chemicals

Two independent labs in China have claimed to be successful in transforming skin cells into neurons using only a chemical approach. Both sets of findings have been published in Cell Stem Cell, with one study using human cells from healthy individuals and Alzheimer’s patients, and the other using mouse cells.

“The studies are scientifically interesting as they are a proof of concept that it is possible to reprogram fibroblasts to become neuron-like cells using small molecules rather than genetic manipulation. The direct differentiation into neurons may reduce the risk of teratoma formation (a tumor which contains elements of tissues such as bone, hair, muscle. It is mostly benign but can also be malignant). However, both studies are very preliminary and open more questions on whether those cells would be able to engraft and survive in vivo, whether they would be functional and whether they would genuinely be safe. Even if all of these were to be true, it would still be questionable whether such an approach would be useful or sufficient to slow down or delay diseases such as Alzheimer’s.”

“These two pioneering studies, one in a mouse and the other in a human system, demonstrated using the example of converting fibroblasts into neurons that is possible to change the fate of cells using chemical compounds only. Interestingly, the two studies used different cocktails of compounds, some of the ingredients were identical or similar and some were quite different. Although we do not know yet how these transdifferentiated neurons would behave in vivo, the implications for regenerative medicine could be enormous. These studies are proof of principle that such simplistic approach is possible and they should encourage other groups to follow their example.”

* ‘Direct conversion of normal and Alzheimer’s disease human fibroblasts into neuronal cells by small molecules’ by Wenxiang Hu et al., published in Cell Stem Cell at 17:00 UK time on Thursday 6 August 2015.

ǂ ‘Small-molecule-driven direct reprogramming of mouse fibroblasts into functional neurons’ by Xiang Li et al., published in Cell Stem Cell at 17:00 UK time on Thursday 6 August 2015.